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Functionalization of cerium oxide nanoparticles by simple biomolecules
Dupkalová, Daniela ; Tsud, Nataliya (advisor) ; Beranová, Klára (referee)
Nanoparticles show a great promise in medical applications such as diagnostics and treatment of various diseases. As the biological environment of the living organism is very complex, an extensive research is needed to put the novel alternatives into practise safely. One of the interesting materials for bioapplications is cerium oxide with its unique antioxidant properties. In this work we characterised three systems of bare, histidine-covered and glycine- covered cerium oxide nanoparticles (Ce NPs) in a form of colloid solutions. Colloid stability and reactivity of NPs solutions in various pH were studied using DLS. AFM imaging was utilized to determine the size distribution of NPs clusters and its dependence on the preparation procedure. Synchrotron radiation-based techniques (SRPES, RPES and NEXAFS) as well as laboratory XPS were implemented to investigate electronic structure of the NPs systems with the focus on characterisation of histidine and glycine bonding to Ce NPs surface.
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Study of Pt-CeOx catalytic layers in simulated fuel cell conditions
Dinhová, Thu Ngan ; Nováková, Jaroslava (advisor) ; Tsud, Nataliya (referee)
The diploma thesis concerns the study of catalytic layers Pt-CeOx used in Proton-Exchange Membrane Fuel Cells. Employing a Transmission Electron Microscope and Near-Ambient Pressure Photoelectron Spectroscopy, morphology, particle size distribution, chemical composition, and effects of fuel cell conditions were studied. This work contributes to the clarification of the dynamic character of the prepared catalytic layers in reactive conditions, which is essential for understanding their catalytic activity and durability.
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Model systems with the use of CeO2 for bioapplication
Bercha, Sofiia ; Tsud, Nataliya (advisor) ; Lykhach, Yaroslava (referee) ; Švec, Martin (referee)
Title: Model systems with the use of CeO2 for bioapplication Author: Sofiia Bercha Department: Department of Surface and Plasma Science Supervisor: Ing. Nataliya Tsud Ph.D., Department of Surface and Plasma Science Abstract: This thesis is focused on the investigation of model systems for bioapplications. Interfaces between biomolecules and inorganic materials were studied by means of advanced surface science techniques with emphasis on the molecular electronic structure and bonding geometry as a function of material morphology and/or molecular deposition method. For the histidine/cerium oxide system it is demonstrated that the morphology of the oxide determines the mechanism of the molecular adsorption. The presence of an aqueous medium does not alter the histidine interaction with the nanostructured cerium oxide. For the adenine/cerium oxide system we have shown that the adenine molecule chemisorbs on CeO2 intact via nitrogen atoms, independent of the oxide morphology and deposition technique. The adenine molecule was found to decompose on a reduced surface of the cerium oxide. Combining experimental and theoretical methods two distinct phases of adenine on CeO2 were found. For adenine/Cu(111) system it was shown that the strong interaction with the surface keeps the molecule intact on the surface till...
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